Operating instructions for S 40-3...S 150-3 series screw compressors
Page 75
Maintenance
6.5
Special maintenance work
Have proportional regu-
lation checked
(Optional accessory for
S series)
Check:
– After approx. 3,000 operating hours, but at least once a year.
1. Setting the operating pressure sensor
Switch-on pressure:p
min
= Final compression pressure – 15 psig.
Switch-off pressure:p
max
= Final compression pressure.
Fig. 6.13: Setting the proportional controller
3. Pressure switch for infinitely variable capacity control
The low pressure switch for the infinitely variable capacity control limits the re-
duction of the quantity delivered and switches the compressor to idling mode
or off completely if the quantity delivered falls below 50%.
2. Setting the proportional controller
Displace the control range of the propor-
tional controller by turning cap (1).
– Increase pressure level: Turn cap
clockwise.
– Reduce pressure level: Turn cap anti-
clockwise.
NOTICE!
Always set the proportional controller higher than the lowest operating pres-
sure value (p
min
)!
